1. Field of the Invention
The present invention relates generally to siliconcontaining compounds, methods for preparation of such compounds, and polymers thereof. More particularly, the present invention relates to silanol-terminated aromatic imide oligomers, methods for the preparation of isomers thereof, and copolymers of such oligomers with siloxane compounds. The present invention also relates to silylterminated aromatic imide compounds and silyl-protected amino silyl compounds which are useful for forming the above-noted oligomers.
2. Description of Related Art
Polyimides are widely used in the electronics and aerospace industry, for example, as coatings, adhesives, interlevel insulators in integrated circuits, and also to form composites and other structures. One such polyimide is Kapton, a trademark of E.I. duPont de Nemours, for a polymer of pyromelletic dianhydride and diaminophenylether. However, Kapton has the disadvantage that it is colored, which degrades its optical properties, and it is susceptible to atomic oxygen degradation, which makes it unsuitable for space applications in low earth orbit. One alternative to Kapton which has been used is Teflon, a trademark of E.I. duPont de Nemours for a poly (tetrafluoroethylene). While Teflon has good optical properties, it suffers from the serious problem of poor adhesion. Yet another alternative material that has been used is silicone. However, despite the good optical properties and good atomic oxygen resistance of silicones, they are impractical because of their poor mechanical properties. Finally, siloxane-polyimides have been developed as described, for example, by Policastro et al, in the publication "Siloxane Polyimides for Interlevel Dielectric Applications," in the Proceedings of the ACS Division of Polymeric Materials: Science and Engineering, Vol. 59, 1988, Los Angeles, California, pages 209-213. However, such polymers are colored, and contain the weak links of the polyalkylene group, which degrades the thermooxidative properties of the polymer.
Thus, a need presently exists for a polymer which has in combination, good optical properties, good thermo-oxidative stability, resistance to atomic oxygen degradation, good mechanical properties, and good processing characteristics.